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Tim S.
Tim S.
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You can download the WPA Supplicant packages from various locations. I used RPMfind.net.

For reference, here are the instructions on configuring WPA Supplicant after installation. (taken from the above wiki)

Enabling wpa_supplicant without NetworkManager, updated version

This update is a simpler method to have a wifi interface connect automatically during the boot process. The original version is available below for reference.

Why an updated version?

  • Simpler to implement
  • More complete instructions
  • Does not change files overwritten by system updates
  • Supports "service network restart" to re-establish a connection

Edit /etc/sysconfig/network-scripts/ifcfg- file

Run iwconfig to find the wifi device. In this sample output, wlan0 is the only one that supports wifi.

# iwconfig lo no wireless extensions. wlan0 IEEE 802.11bgn ESSID:"NETWORKSSID" Mode:Managed Frequency:2.462 GHz Access Point: 68:7F:74:AD:F3:3C Bit Rate=54 Mb/s Tx-Power=16 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:on Link Quality=50/70 Signal level=-60 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:90 Missed beacon:0 eth0 no wireless extensions. pan0 no wireless extensions. virbr0 no wireless extensions. virbr0-nic no wireless extensions. #

Edit the ifcfg for this interface. For example, using wlan0.

/etc/sysconfig/network-scripts/ifcfg-wlan0

Verify that the ONBOOT selection is enabled.

ONBOOT="yes"

Edit /etc/sysconfig/wpa_supplicant

Ensure that your device is included in the INTERFACES line in this file. In this example wlan0 is the only device supported by wpasupplicant.

# Use the flag "-i" before each of your interfaces, like so: # INTERFACES="-ieth1 -iwlan0" INTERFACES="-iwlan0"

Edit /etc/wpa_supplicant/wpa_supplicant.conf

Most of your networks will require a single entry in wpa_supplicant.conf that looks like this. Replace NETWORKSSID and NETWORKPSK with the proper values for each network. Put them in the order that you want them used.

network={ ssid="NETWORKSSID" scan_ssid=1 key_mgmt=WPA-PSK psk="NETWORKPSK" }

Here is an example of a network which doesn't require a Pre Shared Key. If this appears before the "any" network it will be preferred to other open networks.

network={ ssid="PUBLIC" key_mgmt=NONE }

A final option (which you may not choose to implement) will let you connect to any network that is open. This is useful in hotels, but may allow connections to undesirable networks.

network={ key_mgmt=NONE }

Create /etc/rc5.d/S09prepnet

Paste the following text to create a new file which will prepare the running services for a wifi connection.

cat > /etc/init.d/prepnet <<EoT #!/bin/sh /etc/init.d/messagebus start /etc/init.d/wpa_supplicant start killall dhclient >/dev/null 2>&1 EoT chmod a+rx /etc/init.d/prepnet ln -s /etc/init.d/prepnet /etc/rc3.d/S09prepnet ln -s /etc/init.d/prepnet /etc/rc5.d/S09prepnet

Configure services to run at boot

Paste the following commands to configure services.

chkconfig messagebus off chkconfig wpa_supplicant off chkconfig NetworkManager off chkconfig network on

Reboot to enable

Upon the next reboot your wifi connection is enabled when network services start.

Adding or editing wifi networks

If you need to add or edit a wifi network, make whatever changes are needed in wpa_supplicant.conf.

/etc/wpa_supplicant/wpa_supplicant.conf

Next restart wpa_supplicant and network services.

service wpa_supplicant restart service network restart

You can download the WPA Supplicant packages from various locations. I used RPMfind.net.

For reference, here are the instructions on configuring WPA Supplicant after installation. (taken from the above wiki)

Enabling wpa_supplicant without NetworkManager, updated version

This update is a simpler method to have a wifi interface connect automatically during the boot process. The original version is available below for reference.

Why an updated version?

  • Simpler to implement
  • More complete instructions
  • Does not change files overwritten by system updates
  • Supports "service network restart" to re-establish a connection

Edit /etc/sysconfig/network-scripts/ifcfg- file

Run iwconfig to find the wifi device. In this sample output, wlan0 is the only one that supports wifi.

# iwconfig lo no wireless extensions. wlan0 IEEE 802.11bgn ESSID:"NETWORKSSID" Mode:Managed Frequency:2.462 GHz Access Point: 68:7F:74:AD:F3:3C Bit Rate=54 Mb/s Tx-Power=16 dBm Retry long limit:7 RTS thr:off Fragment thr:off Encryption key:off Power Management:on Link Quality=50/70 Signal level=-60 dBm Rx invalid nwid:0 Rx invalid crypt:0 Rx invalid frag:0 Tx excessive retries:0 Invalid misc:90 Missed beacon:0 eth0 no wireless extensions. pan0 no wireless extensions. virbr0 no wireless extensions. virbr0-nic no wireless extensions. #

Edit the ifcfg for this interface. For example, using wlan0.

/etc/sysconfig/network-scripts/ifcfg-wlan0

Verify that the ONBOOT selection is enabled.

ONBOOT="yes"

Edit /etc/sysconfig/wpa_supplicant

Ensure that your device is included in the INTERFACES line in this file. In this example wlan0 is the only device supported by wpasupplicant.

# Use the flag "-i" before each of your interfaces, like so: # INTERFACES="-ieth1 -iwlan0" INTERFACES="-iwlan0"

Edit /etc/wpa_supplicant/wpa_supplicant.conf

Most of your networks will require a single entry in wpa_supplicant.conf that looks like this. Replace NETWORKSSID and NETWORKPSK with the proper values for each network. Put them in the order that you want them used.

network={ ssid="NETWORKSSID" scan_ssid=1 key_mgmt=WPA-PSK psk="NETWORKPSK" }

Here is an example of a network which doesn't require a Pre Shared Key. If this appears before the "any" network it will be preferred to other open networks.

network={ ssid="PUBLIC" key_mgmt=NONE }

A final option (which you may not choose to implement) will let you connect to any network that is open. This is useful in hotels, but may allow connections to undesirable networks.

network={ key_mgmt=NONE }

Create /etc/rc5.d/S09prepnet

Paste the following text to create a new file which will prepare the running services for a wifi connection.

cat > /etc/init.d/prepnet <<EoT #!/bin/sh /etc/init.d/messagebus start /etc/init.d/wpa_supplicant start killall dhclient >/dev/null 2>&1 EoT chmod a+rx /etc/init.d/prepnet ln -s /etc/init.d/prepnet /etc/rc3.d/S09prepnet ln -s /etc/init.d/prepnet /etc/rc5.d/S09prepnet

Configure services to run at boot

Paste the following commands to configure services.

chkconfig messagebus off chkconfig wpa_supplicant off chkconfig NetworkManager off chkconfig network on

Reboot to enable

Upon the next reboot your wifi connection is enabled when network services start.

Adding or editing wifi networks

If you need to add or edit a wifi network, make whatever changes are needed in wpa_supplicant.conf.

/etc/wpa_supplicant/wpa_supplicant.conf

Next restart wpa_supplicant and network services.

service wpa_supplicant restart service network restart
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Tim S.
Tim S.
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Even though your system recognizes the wireless interface, you still need a package in order to manage it. Generally for CentOS, I use WPA Supplicant. It includes the tools you'd use to enable/disable/etc the interface.

A writeup is here on the CentOS wiki.